package com.cbhb.sys;

public class ToLowerCase {

    public static String toLowerCase(String str) {
        StringBuilder sb = new StringBuilder();
        for(char cha: str.toCharArray()) {
            if (cha >= 'A' && cha <= 'Z') {
                cha = (char)(cha -('A'-'a'));
            }
            sb.append(cha);
        }

        return sb.toString();
    }
}
